每个循环向数组添加数字

Question

我最近做了一个快速程序,让计算机猜出你输入的数字.我只是用它来向朋友展示一个While循环的例子.我决定让它变得更复杂,但我不知道该怎么做.

我希望将每个随机猜测添加到数组中,以便它不会多次猜测相同的数字.

Scanner scan = new Scanner (System.in); // Number to guess //
Random rand = new Random(); // Generates the guess //
int GuessNum = 0, RandGuess = 0;

System.out.println("Enter a number 1 - 100 for me to guess: ");
int input = scan.nextInt();

if (input >= 1 && input <= 100)
{
 int MyGuess = rand.nextInt (100) + 1;
   while ( MyGuess != input)
   {
     MyGuess = rand.nextInt (100) + 1;
     GuessNum++;
   }
   System.out.println ("I guessed the number after " + GuessNum + " tries.");
}

Answer 1

您可能想要使用ArrayList(动态增加的数组)

ArrayList<Integer> list = new ArrayList<Integer>();

list.add(num);

如果您想查看该号码是否已添加到arraylist中

if(list.contains(num))
{
 System.out.println("You already tried " + num);
}

A Set也是一个相当好的选择.它与a相同ArrayList但不允许重复.

HashSet<Integer> set = new HashSet<Integer>();

set.add(num);//returns true if the num was not inserted before else return false

if(!set.add(num))//set also has a contains method
{
  System.out.println("You already entered " + num);
}